[R] cube root

Berend Hasselman bhh at xs4all.nl
Sun Apr 17 08:00:59 CEST 2011


Branimir K. Hackenberger wrote:
> 
> This is some interesting:
> 
>> -8^(1/3)
> 
> [1] -2
> 
>> x=(-8:8)
> 
>> y=x^(1/3)
> 
>> y
> 
>  [1]      NaN      NaN      NaN      NaN      NaN      NaN      NaN     
> NaN
> 0.000000 1.000000
> 
> [11] 1.259921 1.442250 1.587401 1.709976 1.817121 1.912931 2.000000
> So, can anybody explain this?! (Why is x[1]^(1/3)=y[1]=NaN, but
> -8^(1/3)=-2?)
> 

Operator precedence.

See R FAQ 7.33 Why are powers of negative numbers wrong?


Berend


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